Tarski's undefinability theorem

E71179

Tarski's undefinability theorem is a fundamental result in mathematical logic showing that, in sufficiently strong formal systems, the notion of truth for the language of the system cannot be defined within that same language.

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Generate an image of Tarski's undefinability theorem (Tarski's undefinability theorem is a fundamental result in mathematical logic showing that, in sufficiently strong formal systems, the notion of truth for the language of the system cannot be defined within that same language.)

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Statements (47)

Predicate Object
instanceOf mathematical theorem ⓘ
result in mathematical logic ⓘ
appliesTo Peano arithmetic ⓘ
arithmetically adequate theories ⓘ
first-order arithmetic ⓘ
formal languages ⓘ
sufficiently strong formal systems ⓘ
concerns definability of semantic concepts ⓘ
limitations of formal systems ⓘ
truth predicates ⓘ
consequence no formula in the language of arithmetic can capture exactly the Gödel numbers of all true arithmetic sentences ⓘ
truth in arithmetic is not arithmetically definable ⓘ
truth is strictly stronger than provability in arithmetic ⓘ
field mathematical logic ⓘ
metalogic ⓘ
model theory ⓘ
formalizes impossibility of defining a global truth predicate for a language within itself ⓘ
historicalPeriod 20th-century logic ⓘ
holdsIn any consistent, sufficiently strong, effectively axiomatizable theory extending Robinson arithmetic ⓘ
implies hierarchy between object language and metalanguage ⓘ
nonexistence of an internal truth predicate for arithmetic ⓘ
semantic notions like truth may require a stronger metalanguage ⓘ
influenced philosophy of language ⓘ
philosophy of mathematics ⓘ
theories of truth in analytic philosophy ⓘ
mainTopic formal theories of truth ⓘ
undefinability of truth ⓘ
motivated development of formal truth theories ⓘ
distinction between object language and metalanguage in logic ⓘ
study of truth hierarchies ⓘ
namedAfter Alfred Tarski ⓘ
relatedTo Gödel's incompleteness theorems ⓘ
Tarski's hierarchy of languages ⓘ
Tarski's semantic conception of truth ⓘ
Tarski–Mostowski–Robinson theorem ⓘ
definability theory ⓘ
liar paradox ⓘ
requires effective axiomatizability of the theory ⓘ
sufficient expressive power to represent arithmetic ⓘ
statesThat no arithmetically definable predicate in the language of arithmetic can coincide with the truth predicate for arithmetic ⓘ
there is no formula in the language of arithmetic that defines the set of all true arithmetic sentences ⓘ
truth for the language of a sufficiently strong theory cannot be defined within that same language ⓘ
typeOf metatheorem about formal theories ⓘ
undefinability result ⓘ
uses arithmetization of syntax ⓘ
diagonalization ⓘ
self-referential sentences ⓘ

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Referenced by (5)

Full triples — surface form annotated when it differs from this entity's canonical label.

liar paradox → relatedTo → Tarski's undefinability theorem ⓘ
Alfred Tarski → knownFor → Tarski’s undefinability theorem ⓘ
linked to: Tarski's undefinability theorem
Gödel's incompleteness theorems → relatedTo → Tarski's undefinability theorem ⓘ
Grelling–Nelson paradox → relatedConcept → Tarski undefinability theorem ⓘ
linked to: Tarski's undefinability theorem
Alfred Tarski → notableWork → Tarski’s undefinability theorem ⓘ
subject linked to: Alfred Teitelbaum
linked to: Tarski's undefinability theorem